If you are concerned about a milkweed bug infestation in your garden, the solution may be complicated. As you probably have guessed, both large and small milkweed bugs feed on the seeds of your milkweed. They deform the milkweed pods and sometimes grow to large numbers.

The tricky part? Milkweed, or Asclepias, is also the sole habitat and food source of monarch caterpillars, which become beautiful monarch butterflies.

Luckily, there are many ways to identify and control your milkweed bug population while preserving monarchs and allowing your garden to thrive.

Milkweed Bug Identification & Life Cycle

Milkweed bugs are “true bugs” in the order Hemiptera, which also includes cicadas, leafhoppers, and shield bugs. They are very hard to miss because of their distinctive black and red orange coloring.

The large milkweed bug, or Oncopeltus fasciatus, has an X shape on its back. The small milkweed bug looks similar, but the red and black pattern is different, and they have small white dots on their wings.

Milkweed bugs have a sucking mouthpart called a rostrum, and they use it to feed on milkweed seeds and sap.

An adult milkweed bug lives about one month and undergoes incomplete metamorphosis.

They begin as bright orange eggs and go through five stages of development, or instars.

The females can reproduce just a few days after birth. Generally, the species can spawn up to three generations per year, depending on climate.

Most milkweed bugs overwinter, which means they find places to hide or hibernate during the colder months.

Eliminating places for bugs to overwinter near your house or garden can be an essential part of pest control. It may directly affect the number of milkweed bugs you see the following season.

Milkweed Bug Infestation – Symptoms and Diagnosis

Fortunately, milkweed bugs are mostly harmless. Still, they can become a nuisance, especially when you are trying to attract and preserve the presence of monarch butterflies.

In mid to late summer, you may begin to see milkweed bugs nymphs in your garden. The nymphs are mostly bright red orange with black wing pads. You may also be able to spot the orange eggs.

It’s easy to see milkweed bugs feeding because they usually do it in patches or swarms.

Scientists believe that one adult bug can signal to the others when there is a viable food source available. They always gravitate towards milkweed, but the bugs can actually survive on watermelon and sunflower seeds as well.

If your milkweed supply is plentiful, you may not find these bugs very bothersome. But if you have a limited amount of milkweed, you will find that they damage and distort the plant.

The milkweed loses all appeal for monarchs, and you won’t have the butterfly population you hope to attract. In these situations, dealing with a milkweed bug infestation can be wise.

Are Milkweed Bugs Harmful to Humans?

The normal milkweed bugs are not harmful to humans. However, many people confuse a milkweed bug bite with the harsh milkweed assassin bug bite, which has similar red and black coloring.

Milkweed assassin bugs are smaller than milkweed bugs, with long legs like a spider. This bug is a predator that eats mostly flies and worms. While they don’t go out of their way to bite humans, they will under certain circumstances.

A milkweed bug bite from an assassin bug can burn and swell for days.

By contrast, milkweed bugs are harmless herbivores.

There are no natural milkweed bug predators, and the bugs themselves only do damage to plants.

It’s up to you to control your milkweed bug population, but you can attack the problem with no fear.

How to Get Rid of Milkweed Bugs

If your milkweed bug infestation has grown out of control and you are concerned about the monarch butterflies, you may be looking for the best way to get rid of them.

The easiest method of getting rid of milkweed bugs is simply to squash them when you see them. You can also drop them into a bucket of soap and water.

If these methods aren’t enough, you can use insecticidal soap to wash your milkweed.

If you are growing milkweed to attract butterflies, it is essential to remember that all pesticides you use to eliminate milkweed bugs can also harm monarchs. Dealing with a true milkweed bug infestation can be challenging because of this.

Chemical Pest Control

There are many chemical bug sprays such as malathion or carbaryl that you can buy at the store.

Carbaryl is typically sold as garden dust or garden tech sevin spray. These will successfully kill milkweed bugs and their eggs.

However, this is usually a last resort when looking for a solution to your milkweed bug infestation. You can harm butterfly eggs and monarchs themselves, as well as other natural pests and predators that are meant to thrive in your garden.

If you find these sprays necessary, it might be wise to spray bugs off of the milkweed with water first. This will help prevent toxic sprays from sticking to your leaves more than necessary.

Organic Pest Control

As previously stated, insecticidal soap is a dependable method for getting rid of milkweed bugs.

Many forms of true bugs can be eliminated even with simple liquid soaps from inside your house.

You can make homemade insecticidal soap by combining pure soap, not dish soap or detergent, with water and other ingredients such as cooking oil or vinegar to improve effectiveness.

Once you coat the milkweed bugs with your soap, make sure that you thoroughly rinse the plants with water so that they are safe for monarchs to feed.

Insecticidal soaps are also sold at home and garden stores. In addition, rubbing alcohol destroys most true bugs.

With some time and patience, you can attack swarms of milkweed bugs using soaked cotton swabs.

The most common organic method of dealing with a milkweed bug infestation is simply to live with the damage. These bugs are only present in your garden for a short period of time, and the effect they have on your milkweed is usually small. You can continue to squish them by hand to control the population.

You can also remove dead leaves and stalks from surrounding areas to remove a possible house for later metamorphosis stages and winter hibernation.

Sometimes, they are fooled by a rare warm day in the colder months and venture out to lay more eggs.

In larger gardens, you can diversify the types of milkweed you grow. If you have a large number of milkweed plants and place them in several different areas, milkweed bugs are likely to stick to one.

This means the damage will be concentrated. Whether you live with the damage or decide to eliminate the bugs, you are more likely to save your butterfly population if you have a certain amount of milkweed you can sacrifice.

Filling your garden with beautiful monarch butterflies is a great way to brighten your summer. However, most experienced gardeners know that some regular pest control is required.

The black and red milkweed bugs may pay you a visit every year, but there’s no need to panic. These harmless bugs are a natural part of the ecosystem and have a relatively short life cycle.

But if they’re chasing away caterpillars and leaving your milkweed damaged, you can easily cut down on the nuisance.